Lee Loader

Read an interesting article yesterday about loading +p Starline brass vs standard Starline brass in 45acp. It's done by American Handgunner---Handloading +P brass.... and has to do with case volume. This is not "new" info by any means, we probably all are aware of this, but how many of us ever really pay THAT much attention to it. Well today I duplicated their test with my own "test" with the only difference being instead of using Starline regular brass I used Federal standard brass. The +p brass I used was Starline, and I used a slightly higher charge of Silhouette powder than they used as I already had a "control" group fired using that powder charge for comparison to todays. Make sense? My numbers (difference between loads) were almost a perfect match to theirs but a bit higher (10fps higher average over their test) perhaps because I used Federal regular brass to their Starline. . A couple quick numbers vs a column of numbers just to ease the pain of such things. The difference (avg) between the SL+P brass vs the Federal standard brass (everything else the same) was 56fps. Case volume does matter, but we all know this, but I didn't think it would be that much a "matter"...a side note, and this was just for my personal curiosity, but it is pertinent to the information, I loaded another set of SL +P brass exactly the same but changed the OAL from 1.230 with a heavy crimp (4 thou) to 1.235 with a lighter crimp (2 thou) and it made an avg. difference of 36fps slower, almost back to the standard brass load. I doubt the crimp made any difference in that, but I did that to check for any difference in ES or SD or accuracy. None noted, all rounds shot about the same right at 2inches at 30ft. None of this is earthshaking news but I did find it interesting and will incorporate this information MORE into future load development for myself. Think about this a moment, If you take a "standard pressure" max load of 7.3grs of Silhouette powder (45acp) using a 230gr Hornady XTP bullet in standard brass, you can turn it into a +P load just by using Starline +P brass, no other changes needed. So what happens if you use a max +P load in SL +P brass? Where does that take you... Hope this is of some use to someone. by the way according to Handgunners test the +P brass holds 1.5 grains less powder than SL regular brass...

EDIT: that would be SILHOUETTE powder, others would/could be different...

Nice work .

Items of note and not directly related to your test but pertaining to the out come .

The higher the pressure goes the more that little bit of space matters .
I've taken to sorting all of the pistol brass after a mixed result in 9mm the load was worked out in Win . Rem consistently failed to eject with variations of the stove pipe from mouth hung on the barrel extension to rim on the next round still in the mag . FC was clean but shot low and any weakness in hold or weak side shooting would allow almost clear stove pipes and other weird ejection , the arm roll and stop in the tender part of the elbow is my favorite .
S&B however showed primer flow via the pin crater and back out . I didn't chronograph that experiment but I would imagine that there was over 200 fps difference between even FC and S&B .

Just an effort to site the difference from 21/23 kpsi to 35kpsi .

RBHarter wrote:I didn't chronograph that experiment but I would imagine that there was over 200 fps difference between even FC and S&B .

This is of great note and some concern.